docs: def datetime_is_iso(date_str):
      """Attempts to parse a date formatted in ISO 8601 format"""
      try:
          if len(date_str) > 10:
              dt = isodate.parse_datetime(date_str)
          else:
              dt = isodate.parse_date(date_str)
          return True, []
      except:  # Any error qualifies as not ISO format
          return False, ['Datetime provided is not in a valid ISO 8601 format']